Photo/Illutration Suttsu town in Hokkaido in 2022 (Ikuro Aiba)

Two municipalities in Hokkaido that have applied for hosting the final deposal site for high-level radioactive waste have received mostly clean bills of health in the first survey and can move on to the next stage. 

The Nuclear Waste Management Organization of Japan (NUMO) on Feb. 13 released the results of a survey of research papers and data, the first of the three-stage site selection process, in Suttsu town and Kamoenai village.

The survey identified only a few areas in these municipalities as clearly unsuitable due to active faults or potentially active volcanoes.

The focus now shifts to whether the local governments will proceed with the second-stage survey involving a boring survey.

High-level radioactive waste, generated from spent nuclear fuel, emits radiation so strong that it can be lethal within 20 seconds of exposure. It needs to be isolated for tens of thousands of years until its radioactivity decreases to the level of natural uranium.

The law enacted in 2000 stipulates that the waste must be buried underground at a depth greater than 300 meters. The disposal site needs to be chosen in areas not at risk of volcanic activity or earthquakes.

The first-stage survey was conducted for the first time nationwide in the two municipalities.

NUMO will present the results to the industry ministry’s council on the same day.

A formal report will be compiled based on experts’ opinions.

The two municipalities expressed their willingness to undergo the first-stage survey in October 2020, with the investigations beginning in November 2021.

NUMO analyzed around 1,500 research papers and data in both municipalities.

It identified candidate areas for the second-stage survey: areas in Kamoenai excluding those within 15 kilometers of Mount Shakotandake; and the entire Suttsu town as well as the entire area beneath its coastal seabed.

The second-stage survey typically takes around four years, while the third-stage survey, which involves testing in a constructed underground facility, will last about 14 years.

Once the ministry’s council approves the reports on the first-stage survey of the two municipalities, NUMO will apply to the ministry for the second-stage survey of the target areas, after a period during which the reports are made available to the public.

If local government heads express opposition at that time, the project cannot proceed to the next stage.

Hokkaido Governor Naomichi Suzuki has consistently opposed the surveys, making it unclear whether either municipality will proceed with the second-stage survey.

The central government provides up to 2 billion yen ($13.4 million) for the first-stage survey and up to 7 billion yen in grants for the second-stage survey to municipalities that have applied.

However, accepting the final disposal facility comes with significant burdens, and so far, only the two municipalities in Hokkaido have applied.

In September 2023, the city assembly of Tsushima, Nagasaki Prefecture, adopted a petition to accept the survey.

But Mayor Naoki Hitakatsu expressed opposition due to concerns over the growing fear among residents of the negative impact on the city’s reputation.

Japan has utilized nuclear power plants for more than half a century despite not having a disposal site, resulting in more than 19,000 tons of spent nuclear fuel accumulating across the country.

(This article was written by Aki Fukuyama and Noboru Okada.)

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